Seat belt retractors in vehicles include blocking means in order to stop a belt webbing extension in a case of restraint, for instance during impact or a strong deceleration of the vehicle, and thus to prevent the vehicle occupant from moving forward. For reducing the load by the belt webbing onto the vehicle occupant in the case of accident, force limiting means are provided which permit a defined belt webbing extension in the case of sufficiently high extending forces. The extension of the webbing is limited due to the restricted deformation behavior of the force limiter.
It is the object of the invention to provide a seat belt retractor which after locking the belt reel permits a defined belt webbing extension and an as small mounting size as possible.